New Jersey already has 9 area codes but will be adding a 10th starting September 17th. The NJ Board of Public Utilities which regulates telecommunications said the Garden State would be running out of 609 area codes in 2018. So they can either redraw the current boundary of an area code or add a new overlaying area code to the existing area which is what will happen in the 609 area. The new area code, 640, will overlay the current 609 area code territory in the central and southeastern parts of the state from Cape May to Trenton. If you already have a 609 number, it won't change, but anyone getting a new number from then on may be assigned the new area code. With the addition of 640, New Jersey will now have 10 different area codes including 862, 973, 201, 551, 908, 732, 848, 856 and 609. If you are in the 609 or 640 areas and you are calling to any other area code like 856 or 973, you will need to add a "1" and then dial the area code and the seven-digit phone number.